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What Is Primary Immune Deficiency?
Primary Immunodeficiency

By Vincent Iannelli, M.D., About.com

Updated October 30, 2004

About.com Health's Disease and Condition content is reviewed by the Medical Review Board

When people are born with a faulty immune system, they are said to have a primary immune deficiency or immunodeficiency. Unlike people with AIDS, caused by the human immunodeficiency virus or HIV, people with primary immunodeficiency (PI) diseases have inherited abnormal changes in the cells of their immune systems. Between 25,000 and 50,000 people suffer from the most serious forms of PI diseases in the United States, but experts believe that many more have milder disease that is not yet diagnosed.

Each type of immune system cell has its own special function and must work together with other types to fight disease effectively. Because there are many different types of cells that make up the immune system, an error in any one of them can disrupt our immune defenses. Depending on the cell and the type of error that occurs, more than 80 different forms of PI diseases are possible. Some are severe, while others cause few or no symptoms. Having any of them makes it easier to get infections and other medical conditions. More boys than girls have PI, and first symptoms often begin in infancy or later in childhood.

Primary care doctors who suspect a patient has a problem with the immune system will run screening tests. If those tests indicate the person's immune system is not functioning normally, the doctor will consult with a special kind of doctor called a clinical immunologist. The immunologist can run special blood tests to find out the exact type of PI disease and how best to treat it. Other experts the doctor may consult include pulmonologists, rheumatologists, gastroenterologists, and hematologists.

For More Information:

reproduced from the National Institute of Allergy and Infectious Diseases Fact Sheet on Primary Immune Deficiency
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